the problem is Poloniex. They have SBD in maintenance for I don't know how long, and people are just panic selling.
Take a look here: https://coinmarketcap.com/currencies/steem-dollars/#markets
Bittrex: $0.94/SBD (I've been monitoring the price on bittrex, as I'm using this exchange, and SBD is sitting around $1)
Poloniex: $0.78/SBD (people panic-sell their SBD, as they want to cash-out)
RE: SBD Price in steady decline - Η τιμή του SBD σε τροχιά σταθερής πτώσης